Microsoft has put Windows updates carrying fixes for Meltdown and Spectre CPU flaws on hold after some PCs with AMD processors failed to reboot post the update.
Microsoft has also described how its firmware updates patching Meltdown and Spectre flaws affect PC performance in a detailed note. According to Microsoft, those using Windows 10 on newer silicon (2016-era PCs with Skylake, Kabylake or newer CPU) should not notice a significant drop in performance as benchmarks show single-digit slowdowns. Those using Windows 10 on older silicon (2015-era PCs with Haswell or older CPU) should expect more significant slowdowns after installing the updates. However, those on Windows 7 and 8 can expect the worst and notice a decrease in overall system performance.
“Because Windows clients interact with untrusted code in many ways, including browsing webpages with advertisements and downloading apps, our recommendation is to protect all systems with Windows Updates and silicon microcode updates,” Microsoft said in its blog post.
Even though Microsoft has issued patches for the two CPU flaws, reports suggest that PCs with AMD processors aren’t taking to the updates too well.
“Microsoft has received reports of some AMD devices getting into an unbootable state after installation of recent Windows operating system security updates. After investigating, Microsoft determined that some AMD chipsets do not conform to the documentation previously provided to Microsoft to develop the Windows operating system mitigations to protect against the chipset vulnerabilities known as Spectre and Meltdown. To prevent AMD customers from getting into an unbootable state, Microsoft has temporarily paused sending the following Windows operating system updates to devices that have impacted AMD processors,” Microsoft wrote on it’s support page.
AMD has also acknowledged the problem and in a statement to the media said, "AMD is aware of an issue with some older generation processors following installation of a Microsoft security update that was published over the weekend."
No further update has been provided by Microsoft or AMD. The Meltdown flaw affects Intel Processors going back more than 10 year, while the Spectre flaw will affect every device running on Intel, ARM and AMD chips.